Regulation of Stromal Derived Factor-1 Mediated Angiogenesis in Ischemic Brain

缺血性脑中基质衍生因子 1 介导的血管生成的调节

• 批准号: 8384158
• 负责人: UMADEVI V WESLEY
• 金额: $ 7.53万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8384158
• 关键词: Angiogenic Factor; Animals; Antidiabetic Drugs; Biological Assay; Bioluminescence; Blood Vessels; Blood flow; Brain; Brain Injuries; CXCL12 gene; CXCR4 Receptors; CXCR4 gene; Caregivers; Cause of Death; Cell Death; Cells; Cerebral Ischemia; Cerebrum; Cleaved cell; Clinical; Clinical Research; Contralateral; Corpus striatum structure; Data; Development; Dipeptidyl Peptidases; Endothelial Cells; Enzyme-Linked Immunosorbent Assay; Enzymes; Event; FDA approved; Fibroblast Growth Factor 2; Flow Cytometry; Foundations; Genetic; Glucose; Goals; Growth; Health; Histocytochemistry; Image; In Vitro; Inflammatory; Injury; Ischemia; Ischemic Stroke; Knock-out; Knockout Mice; Luciferases; MMP2 gene; MMP9 gene; Matrix Metalloproteinases; Measures; Mediating; Middle Cerebral Artery Occlusion; Modeling; Molecular; Morbidity - disease rate; Mus; Neural Crest; Neurons; Oxygen; PECAM1 gene; Patient Care; Patients; Peptide Hydrolases; Plasma; Play; Process; Proteins; RNA; Recovery; Recovery of Function; Regulation; Reperfusion Therapy; Rodent Model; Role; Sampling; Screening procedure; Serum; Side; Site; Staining method; Stains; Stem cells; Stroke; Structure; Testing; Therapeutic; Time; Translating; Transplantation; Up-Regulation; Vascular Endothelial Growth Factors; Vascular blood supply; Western Blotting; Work; angiogenesis; artery occlusion; cell motility; cerebral artery; chemokine; density; deprivation; diabetic patient; disability; efficacy testing; improved; in vivo; inhibitor/antagonist; injured; injury and repair; matrigel; migration; mouse model; nerve stem cell; neuroblastoma cell; neurogenesis; neuron loss; novel; pre-clinical; prevent; relating to nervous system; scaffold; small molecule; spatiotemporal; stroke recovery; stroke therapy

DESCRIPTION (provided by applicant): Stroke is the third leading cause of morbidity and long-term disability. Due to cerebral artery occlusion, ischemic stroke causes a severe reduction in blood supply causing destruction of endothelial integrity and neuronal cell death. Indeed, patients with higher density of cerebral blood vessel show better recovery and survival after stroke. Many inflammatory chemokines support the development of vascular blood supply (angiogenesis) and progenitor cell migration to the site of injury. Particularly, the chemokine stromal derived factor (SDF1) acting via its receptor CXCR4 plays a central role in promoting angiogenesis and progenitor cell recruitment. However, SDF1 is often proteolytically cleaved and inactivated. This process may hinder neural (NPC) and endothelial progenitor cells (EPC) migration and angiogenesis necessary for brain injury repair. Thus preventing SDF1 inactivation is of clinical importance. Although the protease dipeptidyl peptidase 4 (DPPIV) is shown to cleave SDF1, its role in ischemic stroke is unknown. The goal of this proposal is to establish a ground work for evaluating the efficacy of the DPPIV inhibition in enhancing the activity of SDF1 for improved angiogenesis and brain injury repair. Our studies show a correlation between loss of DPPIV and increased levels of SDF1 resulting in increased migratory and angiogenic potential of neural crest stem cell derived neuroblastoma cells. We further observed significantly increased DPPIV expression in the post- ischemic brain. We hypothesize that following focal ischemia, DPPIV up regulation curtails SDF1 activity and thus hinders the migration of progenitor cells to the ischemic region and suppresses subsequent angiogenesis and neurogenesis. We further propose that genetic knockout or small molecule inhibitors of DPPIV increases post-ischemic SDF1 levels, which in turn enhances NPC and EPC migration and angiogenesis in ischemic brain. In this proposal, we will test the predicted inverse correlation between DPPIV expression and SDF1, and CXCR4 levels in mouse brain and serum following transient middle cerebral artery occlusion (MCAO) (Aim 1). We will examine whether genetic loss of DPPIV or small molecule inhibitor of DPPIV enhances EPC recruitment and angiogenesis in vivo ischemic brain and in an in vitro ischemic model of oxygen glucose deprivation. The luciferase expressing NPC/EPC will be transplanted into the contralateral striatum of the mice subjected to MCAO and migrating cells will be tracked using bioluminescence imaging (Aim 2). Importantly, DPPIV inhibitors are FDA approved anti-diabetic drugs that increase circulating EPCs in diabetic patients. Our studies if successful can be translated to pre-clinical and clinical studies for improved angiogenesis and neurogenesis. Results from these studies may provide strong foundation for better understanding of novel targets and mechanisms of brain injury repair and may also open up a new direction for stroke therapy. PUBLIC HEALTH RELEVANCE: Ischemic stroke causes death or long term disability presenting a unique challenge to patients and care givers. Stroke results in sudden decrease in blood flow and neural cell death. Restoring blood flow and neurogenesis is critical for stroke recovery. At present, there are limited therapeutic options to treat stroke patients. Our study represents an important first step in better understanding the novel molecular events that govern neurogenesis and angiogenesis (sprouting of new blood vessels) in the post-ischemic brain and establishes ground work for further testing the efficacy of small molecule inhibitors of DPPIV for improved brain injury repair after ischemic stroke that remains a major health problem in the world.

描述(申请人提供)：中风是导致疾病和长期残疾的第三大原因。由于脑动脉闭塞，缺血性卒中导致血液供应严重减少，导致内皮完整性破坏和神经细胞死亡。事实上，脑血管密度越高的患者在中风后表现出更好的恢复和存活率。许多炎性趋化因子支持血管血液供应(血管生成)的发展和祖细胞向损伤部位的迁移。特别是，趋化因子基质衍生因子(SDF1)通过其受体CXCR4发挥作用，在促进血管生成和祖细胞募集方面发挥核心作用。然而，SDF1经常被蛋白水解性切割和失活。这一过程可能会阻碍神经(NPC)和内皮祖细胞(EPC)的迁移和脑损伤修复所需的血管生成。因此，预防SDF1失活具有重要的临床意义。尽管蛋白酶二肽基肽酶4(DPPIV)被证明能裂解SDF1，但它在缺血性卒中中的作用尚不清楚。这项建议的目的是为评估DPPIV抑制剂在增强SDF1活性以促进血管生成和脑损伤修复方面的有效性奠定基础。我们的研究表明，DPPIV的缺失和SDF1水平的增加之间存在相关性，这会导致神经脊干细胞来源的神经母细胞瘤细胞的迁移和血管生成能力增强。我们进一步观察到DPPIV在缺血后大脑中的表达显著增加。我们推测，局灶性脑缺血后，DPPIV的上调抑制了SDF1的活性，从而阻碍了祖细胞向缺血区的迁移，并抑制了随后的血管生成和神经生成。我们进一步提出，DPPIV的基因敲除或小分子抑制剂增加了缺血后SDF1的水平，这反过来又促进了NPC和EPC在缺血脑中的迁移和血管生成。在这项建议中，我们将测试短暂性大脑中动脉闭塞(MCAO)后小鼠脑和血清中DPPIV表达与SDF1和CXCR4水平之间的预测负相关性(目标1)。我们将研究DPPIV的基因缺失或DPPIV的小分子抑制物是否能在体内缺血脑和体外缺氧缺糖模型中促进EPC募集和血管生成。表达NPC/EPC的荧光素酶将被移植到MCAO小鼠的对侧纹状体内，并将使用生物发光成像技术追踪迁移细胞(目标2)。重要的是，DPPIV抑制剂是FDA批准的抗糖尿病药物，可以增加糖尿病患者的循环内皮祖细胞。我们的研究如果成功，可以转化为改善血管生成和神经生成的临床前和临床研究。这些研究结果可能为更好地理解脑损伤修复的新靶点和机制提供坚实的基础，也可能为卒中治疗开辟新的方向。 公共卫生相关性：缺血性中风导致死亡或长期残疾，对患者和护理人员提出了独特的挑战。中风会导致血液流量突然减少和神经细胞死亡。恢复血液流动和神经再生是中风康复的关键。目前，治疗中风患者的治疗选择有限。我们的研究代表了更好地理解控制缺血后大脑中神经发生和血管生成(新血管萌发)的新的分子事件的重要的第一步，并为进一步测试DPPIV的小分子抑制剂在改善缺血性中风后的脑损伤修复方面的有效性奠定了基础。缺血性中风仍然是世界上的一个主要健康问题。